This episode has one of the most charming openings ever: a bored Vicki wandering round the TARDIS as the Doctor tinkers with his Time TV, Ian reads a ‘far-fetched’ storybook about alien monsters, and Barbara, practical as ever, does some dressmaking. This is all lead up to the big reveal of the Space-Time Visualiser, which can show any event from history, including Abraham Lincoln, Queen Elizabeth and Shakespeare, and the Beatles.

Nearly half the episode is taken up with this. And the next several minutes consist of Ian and Vicki going to explore the surface of a twin-sunned planet while the Doctor and Barbara stay by the TARDIS to catch some rays. I wonder if all this came across as ridiculously self indulgent to the contemporary audience. In retrospect, knowing this is the last chance we ever have to see this excellent TARDIS team letting their hair down, it’s utterly adorable. It also neatly gives us slightly unfamiliar pairings: amazingly the Doctor and Barbara haven’t spent much time together since the first season – which is a crime, given how great they are together (I especially love their bits of comedy business, firstly when Barbara criticises the Doctor’s singing, and then his sense of direction). Ian and Vicki haven’t really been paired up at all (Vicki has mainly paired up with the Doctor, or Barbara for a bit of The Rescue and The Web Planet).

About 20 minutes in things take a sinister turn when Barbara and the Doctor discover they’re being hunted through space and time by a Dalek assassination squad, while Ian and Vicki find an underground crypt infested with horrible octopi. A sandstorm splits them up, and cuts them off from the safety of the TARDIS – and as the episode ends with a Dalek rising like Dracula out of the sands, the summery fun of the first part of the episode is comprehensively undercut.

While all the regulars are on form, this is another particularly magnificent episode for Maureen O’Brien. While Ian and Barbara remain half baffled by the Doctor’s garbled explanations, Vicki takes them all in her stride, operates the Space-Time Visualiser herself, and is, as usual, the most keen to explore where they’ve landed. No wonder the Doctor beams with pride and declares, ‘The child’s just like me, you know. Always wants to know what’s on t’other side of the hill.’

 

Next episode: The Death of Time